Method of preparing a container material



July 16, 1940. M. WAGNER METHOD OF PREPARING A CONTAINER MATERIAL FiledJan. 25, 1957 /NVEN To@ NEL V//V WA GIVE@ A TTORNEYS Patented July 16,1940 UNITED STATES PATENT OFFICE Melvin Wagner, Chicago, Ill., assignorto Thel Liquid Carbonio Corp., Chicago, Ill., a corporation of DelawareApplication January 25, 1937, Serial No. 122,119

Claims.

My invention relates to a method of laminating materials to be used forcontainers that are substantially gas-tight and moisture-proof. Myinvention further relates to a material having 5 these samecharacteristics.

It is my object to provide such a material and method so that theresulting product will be free of all solvent odors, as otherwise suchodors would contaminate the materials in the containers made from thismaterial according to my method. Heretoiore, it has been impossible toprovide laminated materials due to the fact that these solvent odorshave been retained almost indenitely in the material and absorbed by thecontents of the containers.

It is the object of my invention to provide a. new material consistingof coated glassine paper to which is applied to the adhesive coating,after it has been dried and all the solvent driven oii,

strips or a layer of thermoplastic material, such as rubberhydrochloride, synthetic resins and the like.

It is a further object to provide in this connection a method whichemploys a plate or other heating means for preheating the precoated,predried glassine paper only, and to further apply to the heated, coatedglassine paper surface the thermoplastic strips or layer, preferablywith cool rollers, so that there can be no heating or deformation of thethermoplastic medium being applied to the coated glassine sheets.

In the drawing:

Figure 1 is a side elevation of my invention, diagrammaticallyillustrating the method of applying the rubber hydrochloride or similarthermoplastic material to the coated glassine sheet.

Figure 2 is a section on the line 2-2 of Figure 1, showing a sectionthrough the coated glassine sheet.

Figure 3 is a section on the line 3-3 of Figure 2, showing a sectionthrough the combined coated glassine sheet and the thermoplastic sheetapplied thereto.

Referring to the drawing in detail, a sheet I of glassne paper is coatedwith a solvent containing adhesive which permits it to be applied byspraying, roller-coating or wiping, or in any other desired manner. Thiscoating is designated 2.

A typical coating is a thermoplastic varnish made of one of the vinylresins. I do not desire to conne myself to the particular material, solong as it is an adhesive from which solvents, such as toluol or thelike, can be driven away by heating,

air-blasts, etc. This varnish coating is allowed to dry and harden untilall of the solvents have evaporated, either naturally or by someartificial means.

Then this composite sheet, which is designated 3, is unwound from a roll4 thereof, and guided 5 over the guide roll 5, beneath the guide roll 6,over a hot plate 1, the temperature of which ranges from approximately250 to 300 degrees F. This brings the coating back to an adhesive state.The sheet 3 is conveyed to a point away from the 10 hot plate, at whichpoint it is joined by a sheet of rubber hydrochloride or similarthermoplastic material, which is designated Il. This sheet is supplied.from a supply roll 9, over the roller Ill, the roller I I and thencedownwardly to the sheet 15 3. Both; sheets then pass between the steelroll I2 and the rubber roll I3, which are preferably geared togetherthrough the gears I4, I5 and I6. The upper roll is preferably pressed onthe material by the spring I'I. These rolls are known as 20 thecombining rolls. They are preferably cool, and if necessary, may bechilled by a suitable refrigerant. It is also optional to applyrefrigerant rollers at a later stage of the combining operation. Thecomposite sheet is then wound 25 on. a rewind re-roller I8. In thiscondition the sheet is free from any solvent. It can be formed into acontainer, due to the fact that the thermoplastic sheet 8 is capable ofbecoming adhesive, upon the application of heat, and optionally, heat 30and pressure.

Amongst the materials of thermoplastic character for use as a sheet 8,is the material known as Pliofllm.

It will be understood that I desire to compre- 35 hend within myinvention such modications as come within the scope of the claims andthe invention.

Having thus fully described my invention, what 40 I claim as new anddesire to secure by Letters Patent is:

1. In a process of making a laminated sheet, coating a paper sheet witha solvent containing varnish, drying and expelling the solvent there- 45from, heating the paper sheet to render the coating adhesive, and thenapplying thereto a rubber hydrochloride sheet by means of pressure whilethe paper sheet is so adhesive.

2. In a method of forming a laminated sheet 50 material for use inmaking gas-proof containers. comprising coating a ilexible brous sheetwith a varnish containing a solvent, drying and expelling the solventtherefrom, heating said fibrous sheet to render the coating adhesive,and then applying 55 and expelling the solvent therefrom, heating saidsheet to render the coating adhesive, and then applying a sheet ofrubber hydrochloride by means of pressure to unite said sheets.

5. In a method of forming a laminated sheet material comprising coatinga flexible sheet with a varnish containing a solvent, drying andexpelling the solvent therefrom, heating said sheet to render thecoating adhesive, and then applying a sheet of rubber hydrochloride bymeans of 10 pressure to'unite said sheets.

MELVIN WAGNER

